Plural-speed phonograph turntable drive mechanisms



Dec. 22, 1964 H. L. HARTMAN 3,162,447

PLURAL-SPEED PHONOGRAPH TURNTABLE DRIVE MECHANISMS 3 Sheets-Sheet 1Filed April 12. 1951 INVEN TOR. M 06 BY .41, 2

A 7' 7' UIPNE V Dec. 22, 1964 H. L. HARTMAN 3,162,447

PLURAL-SPEEZD PHONOGRAPH TURNTABLE DRIVE MECHANISMS Filed April 12, 19613 Sheets-Sheet 3 IN V EN TOR.

United States Patent. Office 3,162,447 Patented Eec. 22, 1964PLURAL-SPEED PHONOGRAPH TURNTABLE DRIVE li iECHANISMS Herbert L.Hartman, Elyria, Ohio, assignor to The General Industries Company,Elyria, Ghio, a corporation of Ohio Filed Apr. 12, 1961, Ser. No.102,438 9 Claims. (Ql. 2749) My invention relates to plural speed drivemechanisms for phonograph turntables and relates more particularly toimprovements in drive mechanisms therefor particularly adapted fordriving the turntable at either of preferably two speeds.

An object of my invention is to provide, in -a device of the typereferred to, a change of driving speed which can be accomplishedautomatically in one speed change through the medium of the record to beplayed on the turntable and without the use of manual additional controlmeans for speed shift. A further object is to provide, in a device ofthe type referred to, means whereby the speed changes are automaticallyaccomplished during rotation of the turntable.

It is a further object of my invention to provide a speed changer forthe turntable through means mounted centrally of said turntable.

A still further object of my invention is to provide a change of speedfor a turntable through the medium of mounting means for the saidrecords.

Another object of my invention is to provide a simple changer speedmechanism which will be economical to manufacture, being composed of butfew parts, and highly efiicient in use.

Still other objects of my invention and the invention itself will becomeapparent from the following description and the appended drawings, inwhich drawings:

FIGURE 1 is a top plan view of the speed changing mechanism of myinvention; a portion of the turntable being broken away to betterillustrate the speed changing mechanism and an underlying portionthereof being shown in dotted lines;

FIGURE 2 is a transverse sectional view of the modification of myinvention shown in FIGURE 1, showing the mechanism in its playingportion with a record adapted to be driven at 45 r.p.m., indicated asplaced on the turntable;

FIGURE 3 is a view similar to that or" FIGURE 2 showing the mechanism inplaying position with a record placed on the turntable and adapted to bedriven at 33 rpm;

FIGURE 4 is a view of the mechanism of FIGURES 1 to 3 showing the partsin an intermediate speed changing or non-play position; and

FIGURE 5 is an enlarged elevational view partly in section showing moreclearly the idler tread and rotor shaft assembly.

Referring now more particularly to the drawings, in

all of which like parts are designated by like reference characters, atI show a phonograph turntable having a peripheral flange 11. Theturntable 16 as shown has a centralrecess portion 12which is centrallyapertured to afford a spindle opening 13. The spindle 14 comprises ahollow spindle 15 secured to a mounting. plate 16- by means of bushing160, the spindle is being freely rotatable in the bushing 16a, andvertically reciprocal rod 17 is telescoped in spindle 15. The lowermostend of the rod 17 rests on a 1st class generally cruciform shape lever18 having upstanding cars 19 journalled to downwardly extending tabextensions 2t depending from the spindle mounting plate 16. The free end21 of the lever 18 contacts rod means 22 which is slid-ably mounted inidler mount 23 and projects downwardly therefrom, the idler mount beingadapted for horizontal displacement with respect to the turntable flange11 and the different diameter steps 25 and 26 mounted on the rotor shaft27. Idler mount 23 is biased in a manner well known in the art by springmeans 28 into driving engagement with one of the steps of the rotorshaft and a portion of the peripheral flange of the turntable. The idlermount comprises generally a lever 40 having an arm 41 fixedly mounted onpost 49 at the bottom thereof. Fixedly mounted on mounting plate 16 is asecond post 50. Slidably mounted on the posts 49 and 50 is toggle link42, which comprises a pair of axially parallel, laterally interspaced,bearing members 47 and 48 connected by web 51. Hence it will be seenthat when the lever 40 and the post 49 are shifted horizontally, theywill pivot about post 50 due to toggle link 42. The idler mount may havea manually actuable hand lever portion 43, as illustrated, extendingbeyond the outer periphery of the turntable which is adapted to shiftthe lever so that a notch 44 disposed at one side of the lever portion43 is adapted to be swung into locking engagement with a preferablyplastic pin 46 secured to the mounting plate and extending upwardlytherefrom. The pin 46 shown is bifurcated to permit contraction of thepin and secure compressive seating of the same within the notch when thelever is shifted from the playing position shown in FIGURE 1 to aneutral or non-playing position as shown in FIGURE 4 in which latterposition the idler wheel is moved out of engagement with either of therotor steps and the turntable flange.

As illustrated in FIGURE 2, an adapter 30 is provided, preferably ofplastic or like material, comprising a spindle portion 31, a circularskirt portion 32, and securing means such as a lug or plurality of lugs32 are provided which project through the recessed portion 12 of theturntable. The adapter 30 is provided with a socket 33 on its under faceand a compression spring means 34 is provided seated on the socketsurface 33 and the upper surfaces of the recessed portion 12. The skirtportion 32 of the adapter 30 is adapted to act as a centering orlocating spindlefor a record, such as a 45 rpm. record, and when soemployed, as best illustrated in FIGURE 2, the socket surfaces merelycontact the upper surfaces of the rod 17, and an adjustment screw 46mounted within an end of the lever 13 may be adjusted to vary the degreeof movement of the rod 17 and hence the range of tilt of the lever 18and the amount ofvertical' displacement of the idler support pin 22.

When a record, such as a 33 r.p.m., having a relatively smaller diameterspindle opening than the '45 r.p.m.- record illustrated, is placed onthe adapter 30 over the spindle 31, the weight of the record willdepress the adapter against the action of the spring 34, pushing downthe rod 17 against an end of the lever 18, pivoting the latter about thefulcrum 20, causing the opposite end 21 of the lever 18 to rise, pushingup the pin 22 and its associated idler mount and idler pulley 24,wherefor' the idler tread portion 29 will leave the larger diameter step26 with which it is engaged when a 45 r.p.m. record is played and moveupwardly into contact with the smaller diameter step 25 to drive theturntable at 33 rpm. It will be noted that when the 33 r.p.m. record isplaced on the spindle causing idler pulley 24 to ascend into engagementwith smaller diameter step 25 three resisting forces are overcome,namely, the reactive force of spring 34, the weight of idler pulley 24,and finally, the friction existing between the periphery of the idlerpulley 24, and the engagement thereof with the inside of flange 11 andstep 26. In other words, through the medium of an adapter means 31 whichis depressed when a rec- V the scopevof the appended chaims, g

ord having a small center opening as a 33 rpm. rec- I center spindleopening, e.g. a 33 r.p.m. record, from its seated position upon theadapter and turntable, the spring 34 beneath the record centeringadapter forces the adapter to an upper position illustrated in FIG. 2. IHowever, at this point the weight of the idler wheel 24 isn'otsuflicient in and of itself to cause the wheel to drop overthe rotorshaft shoulder provided at 26' since the weight of the idler wheel 24 isnot suflicient to overcome the static friction existing between theperiphery of the idler wheel and the driving surfaces thereof, engagedwith the inner wall of the turntable flange 11 and the step 26. When,however, idler wheel 24 is caused to rotate, this frictional resistanceis signficantly decreased and the weight of idler pulley 24 is thenelfective to cause the same to drop over rotor shaft shoulder 26,causing the periphery of wheel 24 to engage the 45 r.p.m. step 26. Thusit will be seen that when a change is made from a 33 r.p.m. record toa"45 r.p.m. under conditions of rotation of the turntable, the idlerwheel 24 will readily descend from engagement with step 25 to engagementwith step 26. Conversely, when a 33 rpm. record is replaced by a 45 rpm.when the turntable is in a restiposition the speed change will not takeplaceuntil the turntable is rotated when the idler tread 29 descendsinto engagement with step 26. In FIGURE 5 I have illustrated a preferredembodiment of anidler tread surface. It will be noted that as the idlertread 29 descends or ascends the descent or ascent is assisted throughthe provision of a chamfered surface 45 on idler tread 24, bestillustrated in FIGURE 5, which decreases the frictional resistance tomovement. B'y pro- 'viding the chamfered surface 45 with an angle whichis relatively more acute than the taper of the shoulder 26', it willreadily be seen that as the idler tread45 descends or ascends the onlyfrictional resistance encountered will be at the point of contactbetween the surface 45 and shoulder 26' and a more rapid change occursthan would be possible if the taper of the shoulder and tread surfacecoincided. Although it will be obvious that the angular relationshipsbetween surface 45 and shoulder 26' can be varied,,it has been foundthat highly satisfactory results have ensued from the ;use of 30'? and45 angles, respectively, on tread surface 45 and shoulder 26'. p

The rotor shaft pulley steps may have a on the edge of the shoulders butessentially arenot necessarily chamfered. f

Although I have described my invention in connection with a preferredembodiment, I am aware that numerous and extensive departures may bemadetherefrom, without however departing from the spirit of my inventionor What I claim'is: 7 1. In a record player comprising a turntablehaving a dependent peripheralflange, ,mounting means for said turntable,a rotor shaft. having difierent diameter steps thereon, an idler. wheeladapted to beinterposed'in driving engagement with said turntable flangeand one of said steps, movable spindle means centrally located on saidslight break to the said first rod contacting said lever at a pointdistant from the contact of the latter with said first rod, wherebydepression of said first rod means results in a corresponding elevationof said second rod means and thereby effects a desired speed change.

2. In a record player comprising a turntable having a dependentperipheral flange, mounting means for said turntable, a rotor shafthaving different diameter steps thereon, an idler wheel adapted to beinterposed in driving engagement with said turntable flange and one ofsaid steps, movable spindle means centrally located on said turntablefor positioning a record to be played thereon, first rod meansvertically having an end adapted to com tact said centrally locatedspindle means, means interposed between said first rod means and asecond rod means whereby when said first rod means is depressed by meansof contact with said centrally located means the said second rod meansis correspondingly elevated to cause the idler wheel means associatedtherewith to contact the peripheral flange at a different level ofdriving engagement and simultaneously therewith contact a differentdiameter step of the rotor shaft.

3. In a record player comprising a turntable, means centrally located onsaid turntable for positioning a record to be played thereon, said meanshaving a spring-receiving socket portion in the bottom thereof, springmeans positioned in said socket between said turntable and said means,and resiliently biasing the latter into an uppermost position, amounting plate, bushing means mounted on said mounting plate, spindlemeans mounted within said bushing means, rod means mounted in saidspindle means for vertical movement therein and relative thereto, theupper end of said rod adapted to extend through said socket intoengagement with the bottom of said centrally located means, the other.end of said rod adapted to engage apivotable lever causing movementthereof whereby a predetermined speed change is effected.

4. Ina record player comprising a turntablerhaving a dependentperipheral flange, mounting means for said turntable, idler pulley meansadapted to be interposed in driving engagement with said turntableflange and either of a pair of different diameter steps on a rotorshaft, vertically movable adapter means on said turntable forpositioning a record to be played thereon, spring means mounted betweensaid adapter and said turntable, the vertically disposed centrallydepending means secured to said idler wheel, vertically disposedreciprocally movable means contacting .under surfaces of said adaptermeans, means interposed between said verticalmeans, whereby movement ofone of said vertical means caused by a record of predetermined size andcenter opening being .positioned on said adapter, overcomes the force ofsaid .spring and the frictional resistance between the periphery of saididler pulley and said turntable flange and an engaged one of said rotorshaft steps, causing said idler pulleyto ascend into engagement with theother of said rotor shaft steps. I a p 5. In a recordplayer comprising a.turntablehaving a dependentperipheral flange, mounting means for saidturntable, idler pulley means adapted to beinterposed in drivingengagementwith said turntable flangeand either of apair 'ofdifferentdiametersteps on a rotor shaft,

adapter means on said turntable for positioning a record to be playedthereon, the vertically, disposed centrally ,dependingmeans secured tosaid ,idler wheel, vertically disposed reciprocally j movable jme ans Icontacting under surfaces of said adapter means, means. interposedbetween said vertical means, whereby movement of one of said verticalmeans caused by a record havingl'a relatively small center opening "isremoyed'from said turntable and seating engagement with said adaptermeans during rotation thereof, said; idler. pulley means' willautomatically descend into engagement withla step of different diameterto effect the speed change, and "will simultaneously effect movement ofsaid transmission means.v

6. In a record player comprising a turntable having a dependentperipheral flange, mounting means for said turntable, a rotor shafthaving different diameter steps thereon, idler pulley means adapted tobe interposed in driving engagement with said turntable flange and oneof said steps, first rod means, second rod means, and means interposedbetween said first rod means and said second rod means whereby wheneither said rod means is depressed the other rod means is elevated tocause the idler wheel integral therewith to be engaged with a differentlevel of said peripheral flange and a d iferent one of said steps, saididler wheel being mounted on a horizontally and vertically movable idlermount, manually movable lever means being rotatably secured to saididler mount, said lever having a notch in a peripheral portion lockinglyengaging a pin fixed to said mounting means, whereby when said lever isrotated horizontally said pin engages said notch and holds said idlerpulley means in a nonplaying position.

7. The combination of claim 6 wherein said pin is longitudinally slottedin the upper portion thereof allowing for contraction thereof whendisposed in said notch.

8. The combination of claim 7 wherein the slotted pin is made ofplastic.

9. The combination of claim 6 wherein said means fixed to said mountingmeans comprises a vertically disposed post, and wherein said lever isadapted to rotate by means of the rotational engagement thereof with alink means which is mounted for rotation on said post.

References Qited in the file of this patent UNITED STATES PATENTS3,008,720 Ooki Nov. 14, 1961 FOREIGN PATENTS 689,176 Great Britain Mar.25, 1953 1,130,354 France Feb. 5, 1957 1,215,253 France Nov. 16, 19591,246,823 France Oct. 12, 1959

6. IN A RECORD PLAYER COMPRISING A TURNTABLE HAVING A DEPENDENTPERIPHERAL FLANGE, MOUNTING MEANS FOR SAID TURNTABLE, A ROTOR SHAFTHAVING DIFFERENT DIAMETER STEPS THEREON, IDLER PULLEY MEANS ADAPTED TOBE INTERPOSED IN DRIVING ENGAGEMENT WITH SAID TURNTABLE FLANGE AND ONEOF SAID STEPS, FIRST ROD MEANS, SECOND ROD MEANS, AND MEANS INTERPOSEDBETWEEN SAID FIRST ROD MEANS AND SAID SECOND ROD MEANS WHEREBY WHENEITHER SAID ROD MEANS IS DEPRESSED THE OTHER ROD MEANS IS ELEVATED TOCAUSE THE IDLER WHEEL INTEGRAL THEREWITH TO BE ENGAGED WITH A DIFFERENTLEVEL OF SAID PERIPHERAL FLANGE AND A DIFFERENT ONE OF SAID STEPS, SAIDIDLER WHEEL BEING MOUNTED ON A HORIZONTALLY AND VERTICALLY MOVABLE IDLERMOUNT,MANUALLY MOVABLE LEVER MEANS BEING ROTATABLY SECURED TO SAID IDLERMOUNT, SAID LEVER HAVING A NOTCH IN A PERIPHERAL PORTION LOCKINGLYENGAGING A PIN FIXED TO SAID MOUNTING MEANS, WHEREBY WHEN SAID LEVER ISROTATED HORIZONTALLY SAID PIN ENGAGES SAID NOTCH AND HOLDS SAID IDLERPULLEY MEANS IN A NONPLAYING POSITION.